-
Notifications
You must be signed in to change notification settings - Fork 3.6k
/
tun.go
230 lines (200 loc) · 5.69 KB
/
tun.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2017-2022 WireGuard LLC. All Rights Reserved.
*/
package gvisortun
import (
"context"
"fmt"
"net/netip"
"os"
"syscall"
"golang.zx2c4.com/wireguard/tun"
"gvisor.dev/gvisor/pkg/buffer"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/link/channel"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
"gvisor.dev/gvisor/pkg/tcpip/stack"
"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
)
type netTun struct {
ep *channel.Endpoint
stack *stack.Stack
events chan tun.Event
incomingPacket chan *buffer.View
mtu int
hasV4, hasV6 bool
}
type Net netTun
func CreateNetTUN(localAddresses []netip.Addr, mtu int, promiscuousMode bool) (tun.Device, *Net, *stack.Stack, error) {
opts := stack.Options{
NetworkProtocols: []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
TransportProtocols: []stack.TransportProtocolFactory{tcp.NewProtocol, udp.NewProtocol, icmp.NewProtocol6, icmp.NewProtocol4},
HandleLocal: !promiscuousMode,
}
dev := &netTun{
ep: channel.New(1024, uint32(mtu), ""),
stack: stack.New(opts),
events: make(chan tun.Event, 1),
incomingPacket: make(chan *buffer.View),
mtu: mtu,
}
dev.ep.AddNotify(dev)
tcpipErr := dev.stack.CreateNIC(1, dev.ep)
if tcpipErr != nil {
return nil, nil, dev.stack, fmt.Errorf("CreateNIC: %v", tcpipErr)
}
for _, ip := range localAddresses {
var protoNumber tcpip.NetworkProtocolNumber
if ip.Is4() {
protoNumber = ipv4.ProtocolNumber
} else if ip.Is6() {
protoNumber = ipv6.ProtocolNumber
}
protoAddr := tcpip.ProtocolAddress{
Protocol: protoNumber,
AddressWithPrefix: tcpip.AddrFromSlice(ip.AsSlice()).WithPrefix(),
}
tcpipErr := dev.stack.AddProtocolAddress(1, protoAddr, stack.AddressProperties{})
if tcpipErr != nil {
return nil, nil, dev.stack, fmt.Errorf("AddProtocolAddress(%v): %v", ip, tcpipErr)
}
if ip.Is4() {
dev.hasV4 = true
} else if ip.Is6() {
dev.hasV6 = true
}
}
if dev.hasV4 {
dev.stack.AddRoute(tcpip.Route{Destination: header.IPv4EmptySubnet, NIC: 1})
}
if dev.hasV6 {
dev.stack.AddRoute(tcpip.Route{Destination: header.IPv6EmptySubnet, NIC: 1})
}
if promiscuousMode {
// enable promiscuous mode to handle all packets processed by netstack
dev.stack.SetPromiscuousMode(1, true)
dev.stack.SetSpoofing(1, true)
}
opt := tcpip.CongestionControlOption("cubic")
if err := dev.stack.SetTransportProtocolOption(tcp.ProtocolNumber, &opt); err != nil {
return nil, nil, dev.stack, fmt.Errorf("SetTransportProtocolOption(%d, &%T(%s)): %s", tcp.ProtocolNumber, opt, opt, err)
}
dev.events <- tun.EventUp
return dev, (*Net)(dev), dev.stack, nil
}
// BatchSize implements tun.Device
func (tun *netTun) BatchSize() int {
return 1
}
// Name implements tun.Device
func (tun *netTun) Name() (string, error) {
return "go", nil
}
// File implements tun.Device
func (tun *netTun) File() *os.File {
return nil
}
// Events implements tun.Device
func (tun *netTun) Events() <-chan tun.Event {
return tun.events
}
// Read implements tun.Device
func (tun *netTun) Read(buf [][]byte, sizes []int, offset int) (int, error) {
view, ok := <-tun.incomingPacket
if !ok {
return 0, os.ErrClosed
}
n, err := view.Read(buf[0][offset:])
if err != nil {
return 0, err
}
sizes[0] = n
return 1, nil
}
// Write implements tun.Device
func (tun *netTun) Write(buf [][]byte, offset int) (int, error) {
for _, buf := range buf {
packet := buf[offset:]
if len(packet) == 0 {
continue
}
pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{Payload: buffer.MakeWithData(packet)})
switch packet[0] >> 4 {
case 4:
tun.ep.InjectInbound(header.IPv4ProtocolNumber, pkb)
case 6:
tun.ep.InjectInbound(header.IPv6ProtocolNumber, pkb)
default:
return 0, syscall.EAFNOSUPPORT
}
}
return len(buf), nil
}
// WriteNotify implements channel.Notification
func (tun *netTun) WriteNotify() {
pkt := tun.ep.Read()
if pkt.IsNil() {
return
}
view := pkt.ToView()
pkt.DecRef()
tun.incomingPacket <- view
}
// Flush implements tun.Device
func (tun *netTun) Flush() error {
return nil
}
// Close implements tun.Device
func (tun *netTun) Close() error {
tun.stack.RemoveNIC(1)
if tun.events != nil {
close(tun.events)
}
tun.ep.Close()
if tun.incomingPacket != nil {
close(tun.incomingPacket)
}
return nil
}
// MTU implements tun.Device
func (tun *netTun) MTU() (int, error) {
return tun.mtu, nil
}
func convertToFullAddr(endpoint netip.AddrPort) (tcpip.FullAddress, tcpip.NetworkProtocolNumber) {
var protoNumber tcpip.NetworkProtocolNumber
if endpoint.Addr().Is4() {
protoNumber = ipv4.ProtocolNumber
} else {
protoNumber = ipv6.ProtocolNumber
}
return tcpip.FullAddress{
NIC: 1,
Addr: tcpip.AddrFromSlice(endpoint.Addr().AsSlice()),
Port: endpoint.Port(),
}, protoNumber
}
func (net *Net) DialContextTCPAddrPort(ctx context.Context, addr netip.AddrPort) (*gonet.TCPConn, error) {
fa, pn := convertToFullAddr(addr)
return gonet.DialContextTCP(ctx, net.stack, fa, pn)
}
func (net *Net) DialUDPAddrPort(laddr, raddr netip.AddrPort) (*gonet.UDPConn, error) {
var lfa, rfa *tcpip.FullAddress
var pn tcpip.NetworkProtocolNumber
if laddr.IsValid() || laddr.Port() > 0 {
var addr tcpip.FullAddress
addr, pn = convertToFullAddr(laddr)
lfa = &addr
}
if raddr.IsValid() || raddr.Port() > 0 {
var addr tcpip.FullAddress
addr, pn = convertToFullAddr(raddr)
rfa = &addr
}
return gonet.DialUDP(net.stack, lfa, rfa, pn)
}